1. Field of the Invention
The present invention relates to a spring hinge structure, and more particularly to a spring hinge structure, wherein the noise produced during the rotation process may be reduced, and the lifetime of the spring hinge structure may be increased.
2. Description of the Related Art
A conventional spring hinge structure in accordance with the prior art shown in FIGS. 1-4 comprises a first hinge plate 2, a second hinge plate 3, and a restoring control device 4. The first hinge plate 2 is made of metallic material, and is fixed on a door frame (not shown). The first hinge plate 2 has a first side provided with a blade 21, and a second side provided with an upper shaft tube 22 and a lower shaft tube 23 spaced from each other. The blade 21 of the first hinge plate 2 is formed with multiple joint holes 211, so that the blade 21 of the first hinge plate 2 may be locked on the door frame. The upper shaft tube 22 is formed with an arcuate slot 221 for passage of an insertion pin 413. The second hinge plate 3 is made of metallic material, and is fixed on a door plate (not shown). The second hinge plate 3 has a first side provided with a blade 31, and a second side provided with an elongated shaft tube 32 mounted between the upper shaft tube 22 and the lower shaft tube 23. The blade 31 of the second hinge plate 3 is formed with multiple joint holes 311, so that the blade 31 of the second hinge plate 3 may be locked on the door plate. The elongated shaft tube 32 of the second hinge plate 3 has a lower portion formed with a positioning hole 321 for passage of a positioning pin 423. Two washers 33 made of plastic material are mounted between the elongated shaft tube 32 of the second hinge plate 3 and the upper shaft tube 22 and the lower shaft tube 23.
The restoring control device 4 includes an upper spindle 41 mounted in the upper shaft tube 22 of the first hinge plate 2, a lower spindle 42 mounted in the lower shaft tube 23 of the first hinge plate 2, and a spring 43 mounted in the elongated shaft tube 32 of the second hinge plate 3. The upper spindle 41 has a first end provided with a fixing seat 411 secured in a first end of the spring 4, and the lower spindle 42 has a first end provided with a fixing seat 421 secured in a second end of the spring 4. The fixing seat 411 of the upper spindle 41 is formed with a positioning slit 4111 for securing the spring leg 431 formed on the first end of the spring 4, and the fixing seat 421 of the lower spindle 42 is formed with a positioning slit 4211 for securing the spring leg 431 formed on the second end of the spring 4. The upper spindle 41 has a second end formed with multiple adjusting holes 412 for insertion of the insertion pin 413. The lower spindle 42 is formed with a positioning hole 422 located adjacent to the fixing seat 421 of the lower spindle 42 for insertion of the positioning pin 423.
As shown in FIG. 2, an adjusting bar 5 may be inserted through the arcuate slot 221 into one of the adjusting holes 412 to rotate the upper spindle 41 which twists the spring 43 to have a determined restoring torque. Then, the insertion pin 413 may be inserted through the arcuate slot 221 into one of the adjusting holes 412. Thus, the door has an automatic restoring function.
However, it needs to drill the adjusting holes 412 and the positioning hole 422 in the upper spindles 41 and 42 made of metal, and it needs to form the positioning slit 4111 and 4211 in the fixing seat 411 and 421, thereby increasing the cost of fabrication. In addition, the insertion pin 413 is easily detached from the arcuate slot 221. Further, the weight of the door plate exerted on the elongated shaft tube 32 of the second hinge plate 3 and the upper shaft tube 22 and the lower shaft tube 23 of the first hinge plate 2 is applied on the washers 33, so that the washers are easily worn out during long-term utilization, thereby increasing the noise produced during the rotation process. Further, the upper and lower spindles 41 and 42 and the upper and lower shaft tubes 22 and 23 are made of metal, so that the noise is easily produced during the rotation process.
The present invention has arisen to mitigate and/or obviate the disadvantage of the conventional spring hinge structure.
The primary objective of the present invention is to provide a spring hinge structure, wherein the noise produced during the rotation process may be reduced, and the lifetime of the spring hinge structure may be increased.
In accordance with the present invention, there is provided a spring hinge structure, comprising a first hinge plate, a second hinge plate, and a restoring control device, wherein:
the first hinge plate is provided with an upper shaft tube and a lower shaft tube spaced from each other, the second hinge plate is provided with an elongated shaft tube mounted between the upper shaft tube and the lower shaft tube, the restoring control device includes an upper spindle mounted in the upper shaft tube of the first hinge plate, a lower spindle mounted in the lower shaft tube of the first hinge plate, and a spring mounted in the elongated shaft tube of the second hinge plate, the upper spindle has a first end provided with a fixing seat secured in a first end of the spring, the lower spindle has a first end provided with a fixing seat secured in a second end of the spring, a pair of juxtaposed T-shaped mounting rings are mounted between the upper shaft tube of the first hinge plate and the elongated shaft tube of the second hinge plate, and are mounted between the lower shaft tube of the first hinge plate and the elongated shaft tube of the second hinge plate respectively, each of the T-shaped mounting rings includes an annular contact ring, the contact rings of the T-shaped mounting rings are juxtaposed with each other, the contact rings of the T-shaped mounting rings are clamped between the upper shaft tube of the first hinge plate and the elongated shaft tube of the second hinge plate, and are clamped between the lower shaft tube of the first hinge plate and the elongated shaft tube of the second hinge plate.
Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.